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Thorsten Dahmen Roman Byshko Dietmar Saupe Martin Röder Stephan Mantler 《Sports Engineering》2011,14(2-4):95-110
In this study, methods for data acquisition, analysis, modelling, and simulation of performance parameters in road cycling on real tracks were developed and evaluated. A simulator was designed to facilitate the measurement in a laboratory environment. The simulation included real height profiles and a video playback that was synchronised with the cyclist’s current virtual position on the track, and online visualisation of course and performance parameters. Field data obtained on mountain tracks in this study were compared with the state-of-the-art mathematical model for road cycling power, established by Martin et al. (J Appl Biomech 14: 276–291, 1998), which accounts for the gradient force, air resistance, rolling resistance, frictional losses in wheel bearings and inertia. The model described the performance parameters accurately with correlation coefficients of 0.96–0.99 and signal-to-noise ratios of 19.7–23.9 dB. It was shown that the mathematical model could be implemented on an ergometer for simulating rides on real courses, providing similar quality measures when comparing field and simulator measurements. 相似文献
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Leslie G. Roman 《Educational theory》1993,43(3):279-308
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Philip A. Spechler Roman M. Gutierrez Susan F. Tapert Wesley K. Thompson Martin P. Paulus 《Child development》2023,94(4):826-835
Studies suggest prenatal cannabis exposure is associated with mood/behavioral problems in children. However, it is unclear if targeting modifiable domains like sleep behaviors would improve outcomes in exposed youth. Using a causal inference framework, the effect of changing sleep-hours on changing internalizing/externalizing problems in children was examined using the Adolescent Brain Cognitive Development™ study baseline (ages 9–10; collected during 2016–2018) and year-1 follow-up data (N = 9825; 4663 female; 5196 white). Average treatment effects (ATE) indicated that more sleep predicted less internalizing (ATE = −.34, SE = .08, p < .001) and externalizing (ATE = −.29, SE = .07, p < .001) problems over time. However, prenatal cannabis exposure moderated the ATE on internalizing (conditional-ATE = .91, SE = .39, p = .019), whereby participants with exposure (n = 605) did not show any effect of changing sleep-hours on mood (B = .09, SE = .24). 相似文献
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This article examines the diffusion of an e-government innovation, a common e-customs standardized solution, which is currently subject of research in the European Union. One of the goals of the European Union is to achieve trade facilitation as well as to secure import and export. In order to achieve this goal, the European Government aims to have a common e-customs standardized solution. For this reason, the European Government provided an e-government model. However, while the e-government model regulates the boundaries of the e-government elements and provides high-level functional and technical specifications, the adoption part is in the hands of the individual EU member states. Procurement of information technology and implementation of e-customs solutions are not specified. The main goal of this study is, therefore, to identify facilitators and barriers that can influence the adoption of standardized e-customs solutions. The research is based on Rogers' theory of innovation considering the technological, organizational, and environmental context. Within the framework of a European funded project, we conducted our study collecting data from interviews and workshops involving an inhomogeneous group of participants, i.e. stakeholders coming from academy, industry, and governmental institutions. By demonstrating the existence of four generic facilitators (benefits potential of the public sector; procedural improvements and streamlined business processes; avoidance of misinterpretations of standardized regulations; and standardization of processes, messages and data models) and three barriers (slowdown in regulation execution due to missing procedural templates, increased complexity in the standardization process itself, electronification of operations) related to customs management, the article contributes towards the research in diffusion and adoption of e-government standards and in particular of standardized e-customs solutions as well as political and societal impact of e-customs policies. 相似文献
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Roman Farana Timothy Exell Gerda Strutzenberger Gareth Irwin 《European Journal of Sport Science》2018,18(3):423-430
Biophysical loading of the elbow and wrist is a potential reason for chronic lesions in gymnastics and present a real concern for coaches, scientist and clinicians. Previous research has identified injury risk factors during round-off (RO) skills in elite female gymnasts. The aim of this study was to investigate key elbow and wrist joint injury risk factors during different techniques of fundamental cartwheel (CW) and RO skills performed by young female artistic gymnasts. Seventeen active young female gymnasts performed 30 successful trials of both CW and RO from a hurdle step with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic (240?Hz) and kinetic (1200?Hz) data were collected for each trial. One-way repeated measures ANOVA and effect size (ES) were used for statistical analysis. The results showed statistically significant differences (P?0.8) among hand positions for peak vertical ground reaction force (VGRF), peak elbow compression force, peak wrist compression force, elbow internal adduction moment and wrist dorsiflexion angle. In conclusion, the parallel and reverse techniques increase peak VGRF, elbow and wrist compression forces, and elbow internal adduction moment. These differences indicate that the parallel and reverse techniques may increase the potential of elbow and wrist injuries in young gymnasts compared with the T-shape technique; this is of particular importance with the high frequency of the performance of these fundamental skills. 相似文献
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Martin Schnitzer Janette Walde Sabrina Scheiber Roman Nagiller Gottfried Tappeiner 《European Journal of Sport Science》2018,18(5):722-730
On the basis of the Youth Olympic Games (YOG), we assess if and how the youth in the communities of the YOG host cities have been influenced concerning their perception of the Olympic values (OV) and the Olympic movement (OM). Special attention of the study is paid to the analysis of intervention mechanisms which the local youth underwent (e.g. attending the YOG on-site, participating in school programmes). Our study was conducted among 1004 adolescents living in the host region three years after the Innsbruck 2012 YOG had been staged. Our analyses extend the corresponding literature by (1) showing that the YOG and the involvement of the local youth in such an event have the power of creating an interest in the OM and its events, but do not have the power to influence the young citizens’ perception of the OV significantly; (2) illustrating that the perception adolescents have of the OV depend mainly on their socio-demographic background, their a priori interest in sports events, social capital (norms, institutional trust) and the extent to which the youngsters follow the event in the different media; and (3) corroborating the hypothesis that intervention programmes (e.g. school programmes) for promoting (Olympic) values and ideals should not be single, obligatory and isolated activities. We conclude that it is not surprising that the International Olympic Committee has reformulated the goals for the YOG in the Olympic Agenda 2020, as some goals relating to the promotion of the OV might have been a mission impossible. 相似文献
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Hurricane Sandy Exposure Alters the Development of Neural Reactivity to Negative Stimuli in Children 
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下载免费PDF全文 Ellen M. Kessel Brady D. Nelson Autumn Kujawa Greg Hajcak Roman Kotov Evelyn J. Bromet Gabrielle A. Carlson Daniel N. Klein 《Child development》2018,89(2):339-348
This study examined whether exposure to Hurricane Sandy‐related stressors altered children's brain response to emotional information. An average of 8 months (Mage = 9.19) before and 9 months after (Mage = 10.95) Hurricane Sandy, 77 children experiencing high (n = 37) and low (n = 40) levels of hurricane‐related stress exposure completed a task in which the late positive potential, a neural index of emotional reactivity, was measured in response to pleasant and unpleasant, compared to neutral, images. From pre‐ to post‐Hurricane Sandy, children with high stress exposure failed to show the same decrease in emotional reactivity to unpleasant versus neutral stimuli as those with low stress exposure. Results provide compelling evidence that exposure to natural disaster‐related stressors alters neural emotional reactivity to negatively valenced information. 相似文献
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Getting to No: Pragmatic and Semantic Factors in Two‐ and Three‐Year‐Olds' Understanding of Negation 下载免费PDF全文
下载免费PDF全文 Although infants say “no” early, older children have difficulty understanding its truth‐functional meaning. Two experiments investigate whether this difficulty stems from the infelicity of negative sentences out of the blue. In Experiment 1, given supportive discourse, 3‐year‐olds (N = 16) understood both affirmative and negative sentences. However, with sentence types randomized, 2‐year‐olds (N = 28) still failed. In Experiment 2, affirmative and negative sentences were blocked. Two‐year‐olds (N = 28) now succeeded, but only when affirmatives were presented first. Thus, although discourse felicity seems the primary bottleneck for 3‐year‐olds' understanding of negation, 2‐year‐olds struggle with its semantic processing. Contrary to accounts where negatives are understood via affirmatives, both sentence types were processed equally quickly, suggesting previously reported asymmetries are due to pragmatic accommodation, not semantic processing. 相似文献